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~~ <br />• <br /> <br />E~~%VECi4 <br />January 24, 2005 <br />Mr. Daniel Mathews <br />Division of Minerals and Geology <br />701 South 3~, Suite 301 <br />Grand Junction, CO 8]501 <br />(970) 242-5025 <br />RE: Seneca II-W Mine Permit C-82-057 <br />TR-49 -Response to 2^^ Round of Adequacy Comments <br />Dear Mr. Mathews: <br />RECEIVED <br />JAN 21 2005 <br />Division sf Minerals and Geology <br />Enclosed, please End two copies of revised and/or additional information for TR-49 addressing the <br />Adequacy Comments of your January 14, 20051etter. A third copy has been sent to the Division's Denver <br />of&ce also addressed to you. The responses to each of the adequary comments are provided below and aze <br />number accordingly. <br />7. Item resolved <br />2. ReJOlution of the '!1 "Pit skde Stabilit arralysir concern ident~ed in the Division i initial adeguac3~ review letter is on bold <br />pending Suhmirtal of updated digital photo8raphy and associated evaluation of the Jtabi/it~~ analyJlJ aJJampZlOnJ by .rCC. <br />Please submit this information byJanuary 31, 2005. <br />Response: SCC had the geotechnical specialist review the original stability analysis assumptions and results <br />to determine the degree of conservatism built into the original analysis. The original failure occurred in virgin <br />material on slopes approxirnately 2.SH:1 V. The original analysis assumed the slope consisted of backfilled <br />material and conducted a back analysis, which resulted in a friction angle of 2]degrees based on a cohesion <br />factor of 0. Since this material was not loose backfill it can be assumed that there is inherent cohesion. <br />Therefore SCC believes that the 3H:] V slope will remain stable but will monitor it for any sign of instabilih~. <br />Attached is a letter from the geotechnica] specialist Qohn Pellicer, MWfi) discussing the original stabilit}' <br />analysis and the current slope conditions. In addition, a disk udth the digital information for the "A" Pit <br />slide area is attached. <br />3. Our underrtandin8 is that the new backfill andgradinB plan being prepared forpendanq PA-05 tvill include the Stability <br />demorutratioru pursuant to Rule 4.14.1(2)(e) arrd 4.19.2(1)(6). Please confimt, and confirm the planned <br />PR-05 submittal date (tentative date otJanuary 31, 2005 was indicated in the TR-49 adequacy <br />response cover /ewer). <br />Response: SCC continues to work on the PR-05 submitta), however the major change in the mine plan and <br />the associated disturbance configuration requires in-depth and detailed planning to make the backfill and <br />grading work to meet all requirements for final grading. SCC expects to submit PR-05 in February 2005, <br />9. Item resolved <br />Seneca Coal Com <br />Seneca Coal Company • P.O. Box 670 • Hayden, Colorado 81639 <br />Telephone (970) 276-3707 • FAX (970) 276-3014 <br />